Re: [PATCH] Fix possible alignment issue with dw2-dir-file-name test case

Pedro Alves
2014-01-10T11:29:06Z

On 01/08/2014 06:00 PM, Andreas Arnez wrote:
> Since upstream gcc has recently increased the function alignment on
> S390, the dw2-dir-file-name test case fails in the first
> gdb_continue_to_breakpoint. Indeed, the breakpoint is now placed into
> the alignment gap *before* the actual function.
>
> This happens because the test case declares the respective "*_start"
> symbol as a "loose" label before the function definition, and the
> compiler inserts the alignment between that label and the function
> itself. The fix defines the "*_start" symbol as a global alias to the
> function instead.

It seems the _start symbol only needs to exist because
the functions were declared static:

> -#define FUNC(name) \
> - asm (#name "_start: .globl " #name "_start\n"); \
> - static void \
> - name (void) \

But I see nothing that needs them to be static. This
seems simpler to me:

---
gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c | 3 +--
gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp | 6 +++---
2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c
index 21a4d2a..2b9cc6a 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c
+++ b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c
@@ -64,8 +64,7 @@ FUNC (compdir_absolute_ldir_absolute_file_absolute_same) \
FUNC (compdir_absolute_ldir_absolute_file_absolute_different)

#define FUNC(name) \
- asm (#name "_start: .globl " #name "_start\n"); \
- static void \
+ void \
name (void) \
{ \
v++; \
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp
index 7f29581..e523e89 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp
@@ -54,7 +54,7 @@ proc out_cu { name cu_dir cu_name line_dir line_name } {
.ascii \"GNU C\\0\" /* DW_AT_producer */
.byte 2 /* DW_AT_language (DW_LANG_C) */
.4byte .Lline_${name}_begin /* DW_AT_stmt_list */
- .4byte ${name}_start /* DW_AT_low_pc */
+ .4byte ${name} /* DW_AT_low_pc */
.4byte ${name}_end /* DW_AT_high_pc */
"
if { $cu_dir != "" } {
@@ -65,7 +65,7 @@ proc out_cu { name cu_dir cu_name line_dir line_name } {

.uleb128 3 /* Abbrev: DW_TAG_subprogram */
.asciz \"${name}\" /* DW_AT_name */
- .4byte ${name}_start /* DW_AT_low_pc */
+ .4byte ${name} /* DW_AT_low_pc */
.4byte ${name}_end /* DW_AT_high_pc */

.byte 0 /* End of children of CU */
@@ -122,7 +122,7 @@ proc out_line { name cu_dir cu_name line_dir line_name } {
.byte 0 /* DW_LNE_set_address */
.uleb128 5
.byte 2
- .4byte ${name}_start
+ .4byte ${name}
.byte 1 /* DW_LNS_copy */
.byte 3 /* DW_LNS_advance_line */
.sleb128 1 /* ... to 1000 */
--
1.7.11.7